Effects of adenosine and epidermal growth factor on the growth of mouse mammary epithelial cells.

The objective of this study was to determine if adenosine alters growth of mammary epithelium. Mouse mammary epithelial cells (NMuMG) were cultured in DMEM supplemented with 10% fetal calf serum. After serum starvation for 24 h, EGF (0-100 ng/ml) and/or adenosine (0-100 microM) was added. Adenosine at concentrations of 1, 10 or 100 microM increased DNA synthesis significantly, when compared to control. Addition of epidermal growth factor (EGF) (10 ng/ml) into 1 or 10 microM adenosine showed the interaction in DNA synthesis between EGF and adenosine. A similar result was observed when 100 microM adenosine added to various concentrations of EGF (0-100 ng/ml). In the second mammary gland (thoracic) organ culture studies, mammary development scores were increased by adenosine (100 microM), EGF (100 ng/ml) and adenosine plus EGF. These results indicate that the purine nucleoside adenosine stimulates mammary epithelial cell growth and interacts with EGF in DNA synthesis of mouse mammary epithelial cells.